From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH 1/2] mmc: block: mmcblkN: use slot index instead of dynamic name index Date: Mon, 06 Aug 2012 11:31:17 -0400 Message-ID: <8739402g1m.fsf@octavius.laptop.org> References: <1344237900-14815-1-git-send-email-dirk.behme@de.bosch.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from void.printf.net ([89.145.121.20]:35944 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755529Ab2HFPbZ (ORCPT ); Mon, 6 Aug 2012 11:31:25 -0400 In-Reply-To: <1344237900-14815-1-git-send-email-dirk.behme@de.bosch.com> (Dirk Behme's message of "Mon, 6 Aug 2012 09:24:59 +0200") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Dirk Behme Cc: linux-mmc@vger.kernel.org, linaro-dev@lists.linaro.org, linux-embedded@vger.kernel.org, Jassi Brar Hi, On Mon, Aug 06 2012, Dirk Behme wrote: > On embedded devices, often there is a combination of removable mmc > devices (e.g. MMC/SD cards) and hard wired ones (e.g. eMMC). > Depending on the hardware configuration, the 'mmcblkN' node might > change if the removable device is available or not at boot time. > > E.g. if the removable device is attached at boot time, it might > become mmxblk0. And the hard wired one mmcblk1. But if the removable > device isn't there at boot time, the hard wired one will become > mmcblk0. This makes it somehow difficult to hard code the root device > to the non-removable device and boot fast. > > This change does simply associate 'N' of 'mmcblkN' with the slot index > instead of the dynamic name index. The slot index is always the same, > ensuring that the non-removable mmc device is associated always > with the same mmcblkN. Independent of the availability of the removable > one. I like this change in principle, but doesn't it break boot for everyone currently using e.g. root=/dev/mmcblk0p1 on slot index 2? That doesn't sound like an acceptable regression. Thanks, - Chris. -- Chris Ball One Laptop Per Child